Power supply device having load detection function and communication apparatus provided with the power supply device

ABSTRACT

A power supply device of the invention includes: a supply section that supplies power to a second processing device which processes data in response to processing execution by a first processing device which processes data; a load detection section that detects a load of processing execution by the first processing device; and a power control section that causes the supply section to increase or decrease power supply according to the magnitude of load detected by the load detection section. The load of processing execution by the first processing device disposed in the upstream side relative to the second processing device is detected, and power supply to the second processing device is increased or decreased according to the detected magnitude of load. Accordingly, even when the amount of processing data sharply increases, sufficient power can be unfailingly supplied to the second processing device.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a power supply device that supplieselectric power to a processing device, and a communication apparatusthat performs a communication processing.

2. Description of the Related Art

In conventional art, electric apparatuses such as a communicationapparatus or server apparatus are each provided with a power supplydevice that supplies electric power to ICs and the like that executevarious types of processings; and electric power must be stably suppliedto this power supply device at all times. Particularly, voltagesoutputted to the ICs and the like need to be regulated at a constantlevel.

FIG. 1 is a schematic configuration diagram of a power supply devicethat supplies electric power to an electric apparatus.

The power supply device 10 illustrated in FIG. 1 is an analog controltype power supply device using analog elements such as an amplifier anda comparator, which regulates the voltage outputted to ICs and the like.

The power supply device 10 includes a voltage detection circuit 11,error amplifier 12, compensation circuit 13, reference oscillator 14,comparator 15, switching element 16 and smoothing filter 17.

First, the voltage detection circuit 11 detects power source outputvoltage Vout currently outputted from the power supply device 10 to ICsand the like. The detected output voltage Vout is sent to the erroramplifier 12. The error amplifier 12 amplifies and outputs a differencebetween output voltage Vout and reference voltage V0. The compensationcircuit 13 regulates amplification voltage Vg outputted from the erroramplifier 12 at a value suitable for the sensitivity of the comparator15.

The reference oscillator 14 outputs voltage signal Vp of a sawtoothwaveform at a given frequency. The comparator 15 compares voltage signalVp of a sawtooth waveform outputted from the reference oscillator 14with amplification voltage Vg regulated by the compensation circuit 13,and sends a control signal to the switching element 16, wherein thecontrol signal turns on when voltage signal Vp of a sawtooth waveform issmaller than amplification voltage Vg, and turns off otherwise.

ON/OFF control of the switching element 16 is performed by use of thecontrol signal sent from the comparator 15, so that the pulse width ofinput voltage Vin inputted to the power supply device 10 is regulated;and the smoothing filter 17 executes a smoothing processing.Consequently, output voltage Vout having a regulated voltage value isoutputted from the power supply device 10 to the electric apparatus. Forexample, when output voltage Vout detected by the voltage detectioncircuit 11 lowers, the difference calculated by the error amplifier 12between output voltage Vout and reference voltage V0 increases. As aresult, voltage signal Vp of a sawtooth waveform becomes smaller thanamplification voltage Vg and thus “ON” time of the control signaloutputted from the comparator 15 lengthens to increase the pulse widthof input voltage Vin. Thus, output voltage Vout rises.

As described above, control is performed in the power supply device 10so that the output voltage outputted to the processing section is keptconstant.

In recent years, as power saving of electric apparatuses andminiaturization of batteries progress, there is increasing demand forlower-voltage application of various components and ICs etc.constituting an electric apparatus. Thus, the current flowing into thesecomponents and ICs tends to increase. Further, in the communicationapparatuses, server apparatuses and the like, the current flowing intoan IC which executes a communication processing can sharply increase insuch a manner that interlocks with the traffic state of communication;in this case, the originally low voltage applied to the IC may furtherlower and fall below a minimum voltage allowing execution of thecommunication processing, thus causing a trouble such as signalinterruption.

In this regard, Japanese Patent Laid-Open No. 9-154275 has disclosed atechnique of providing a power supply device with a capacitor for softstart and thereby reducing a sharp change in current at the time ofturning on or turning off the power supply. When current is variedsmoothly at the time of turning on or turning off the power supply, theinternal circuit can be prevented from being overloaded by a peakcurrent during start-up of the power supply, or from malfunctioning dueto voltage reduction; these are now posing a problem for electricapparatuses for which large-current application has progressed.

However, the technique described in Japanese Patent Laid-Open No.9-154275 cannot cope with a sharp change in current caused by anincrease in load in a processing intermittently performed, such as acommunication processing.

In the conventional analog control type power supply devices, theswitching frequency is raised to improve the response of power supply;power supply is regulated in a manner following a sharp change inprocessing load. However, with only this regulation of switchingfrequency, it is difficult to further improve the response of powersupply.

SUMMARY OF THE INVENTION

The present invention has been made in view of the above circumstancesand provides a power supply device and communication apparatus in whichpower can be stably supplied irrespective of processing load.

The power supply device according to the present invention includes:

a supply section that supplies power to a second processing device whichprocesses data in response to processing execution by a first processingdevice which processes data;

a load detection section that detects a load of processing execution bythe first processing device; and

a power control section that causes the supply section to increase ordecrease power supply according to the magnitude of load detected by theload detection section.

According to the power supply device of the present invention, the loadof processing execution by the first processing device disposed in theupstream side relative to the second processing device is detected, andpower supply to the second processing device is increased or decreasedaccording to the detected magnitude of load. Accordingly, even when theamount of processing data sharply increases, sufficient power can beunfailingly supplied to the second processing device.

In the power supply device of the present invention, it is preferablethat: in the supply section, voltage is variable in supplying power; andthe power control section causes the supply section to increase ordecrease power supply by raising or lowering the voltage of the supplysection.

When the voltage applied to the second processing device lowers, thereis a risk that the processing cannot be executed, or a large currentflows in the second processing device and thus a malfunction occurs dueto heating or overload. When power supply is increased or decreased byraising or lowering of voltage, the processing can be stably executed inthe second processing device.

In the power supply device of the present invention, it is preferablethat the first processing device and the second processing device areincorporated in a communication apparatus and serve to apply acommunication processing to data communicated by the communicationapparatus.

In the communication apparatus, the load of processing execution largelyincreases or decreases according to the amount of transmitted/receiveddata, so the power supply device of the present invention can beappropriately used.

The communication apparatus according to another aspect of the inventionincludes:

a first processing section that serves to apply a first communicationprocessing to data;

a second processing section that serves to apply a second communicationprocessing to data in response to processing execution by the firstprocessing section;

a supply section that supplies power to the second processing section;

a load detection section that detects a load of processing execution bythe first processing section; and

a power control section that causes the supply section to increase ordecrease power supply according to the magnitude of load detected by theload detection section.

According to the communication apparatus of this aspect of theinvention, even when communication data sharply increases, reliablecommunication processing execution is possible.

In the communication apparatus of this aspect of the invention, it ispreferable that: in the supply section, voltage is variable in supplyingpower; and the power control section causes the supply section toincrease or decrease power supply by raising or lowering the voltage ofthe supply section.

Since power supply is increased or decreased by raising or lowering ofvoltage, processing stability can be improved.

As described in the above, according to the present invention, power canbe stably supplied to the processing device irrespective of processingload, and thus reliable processing execution is possible.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram of a power supply devicethat supplies electric power to an electric apparatus;

FIG. 2 is an external perspective view of a communication unit to whichan embodiment of the present invention is applied;

FIG. 3 is a perspective view of a holding board;

FIG. 4 is a schematic view of an electrical circuit package;

FIG. 5 is a schematic functional block diagram of three electricalcircuit packages of the plural electrical circuit packages illustratedin FIG. 2;

FIG. 6 is a schematic configuration diagram of a power supply source, apower control circuit, and a processing circuit in a signal processingpackage;

FIG. 7 is a schematic configuration diagram of the power supply source,power control circuit, and processing circuit of the signal processingpackage illustrated in FIG. 6;

FIG. 8 is a view illustrating a flow of data transmitted between a powercontrol circuit and PWM control circuit;

FIG. 9 is a conceptual view illustrating power supplied from each of thethree power supply sources to the processing circuit; and

FIG. 10 is a schematic configuration diagram of a power supply source, apower control section, and a processing circuit in a signal processingpackage according to a third embodiment.

DETAILED DESCRIPTION OF THE INVENTION

An embodiment of the present invention will be described below.

FIG. 2 is an external perspective view of a communication unit to whichan embodiment of the present invention is applied.

This communication unit 100 serves to transmit/receive data via anetwork, and includes a unit cover 101, a unit frame 102, a back panel103, and plural electrical circuit packages 200 contained in a spacesurrounded by these parts, which each execute a processing.

In the interior side of the back panel 103, there are arranged varioustypes of connectors (not illustrated) for transmitting data and electricpower. These connectors are fit in connectors arranged in each of theplural electrical circuit packages 200, so that the plural electricalcircuit packages 200 are connected to each other.

The plural electrical circuit packages 200 serve to apply a processing,one after the other, on communication data received via a network; inresponse to processing execution by the former-stage electrical circuitpackage 200, processing execution in the latter-stage electrical circuitpackage 200 starts. The electrical circuit packages 200 each include asubstrate 220 (refer to FIG. 4) having mounted thereon ICs and the like,and a holding board 210 (refer to FIG. 3) that holds the substrate 220.

FIG. 3 is a perspective view of the holding board 210 constituting theelectrical circuit package 200. FIG. 4 is a schematic view of theelectrical circuit package 200 having the substrate 220 mounted on theholding board 210.

The holding board 210 includes: a grasping section 211 for grasping theholding board 210 by a hand in inserting and removing the holding board210 from the unit frame 102 of FIG. 2; a power source connector 212 afor supplying power to the electrical circuit package 200; a warpageprevention matallic member 213 for preventing warpage of the substrate220; and a data connector 212 b for transmitting and receiving varioustypes of data.

FIG. 4 illustrates the electrical circuit package 200 having thesubstrate 220 mounted in the holding board 210. Arranged in thesubstrate 220 are plural processing circuits 221 such as an IC, a powersupply source 223 for supplying power to the plural processing circuits221, and the like. When the substrate 220 is fit in the holding board210, so that the power source connector 212 a and data connector 212 bof the holding board 210 are inserted in the substrate 220, thesubstrate 220 is mounted on the holding board 210. Further, when theholding board 210 is fit in the unit frame 102 illustrated in FIG. 2 andis connected to the connectors of the back panel 103, the pluralelectrical circuit packages 200 are connected to each other.

FIG. 5 is a schematic functional block diagram of three electricalcircuit packages 200_1, 200_2 and 200_3 of the plural electrical circuitpackages 200 illustrated in FIG. 2.

Respective elements constituting each of the three electrical circuitpackages 200_1, 200_2 and 200_3 will be described below while making adistinction between them by use of suffix numerals.

FIG. 5 illustrates an optical interface package 200_1 that receivesoptical data transmitted via a network; an electrical interface package200_2 that converts the optical data received by the optical interfacepackage 200_1 into digital data; and a signal processing package 200_3that applies various types of signal processings to the digital dataobtained by the conversion by the electrical interface package 200_2.According to the present embodiment, firstly power is supplied to thewhole communication unit 100 illustrated in FIG. 2, and then that poweris distributed to the respective power supply sources 223 of the pluralelectrical circuit packages 200, and thereafter the power is suppliedfrom the power supply source 223 to the processing circuit 221 in eachof the electrical circuit package 200.

The electrical interface package 200_2 includes a current detectioncircuit 225_2 that detects a current value flowing into the processingcircuit 221_2 during processing execution. The signal processing package200_3 includes a power control section 224_3 that acquires the currentvalue detected by the current detection circuit 225_2 of the electricalinterface package 200_2 and regulates power supply by the power supplysource 223_3 according to the acquired current value. The processingcircuit 221_2 of the electrical interface package 200_2 corresponds toan example of the first processing device and the first processingsection according to the present invention; the processing circuit 221_3of the signal processing package 200_3 corresponds to an example of thesecond processing device and the second processing section according tothe present invention; the current detection circuit 225 ₁₃ 2 of theelectrical interface package 200_2 corresponds to an example of the loaddetection section according to the present invention; the power supplysource 223_3 of the signal processing package 200_3 corresponds to anexample of the supply section according to the present invention; andthe power control section 224_3 corresponds to an example of the powercontrol section according to the present invention.

FIG. 6 is a view for explaining a flow of power supply in the signalprocessing package 200_3.

The signal processing package 200_3 includes, as illustrated in FIG. 6,plural processing circuits 221A, 221B, 221C, 221D and 221E. Plural powersupply sources 223A, 223B, 223C, 223D, and 223E are connected to theprocessing circuits 221A, 221B, 221C, 221D and 221E, respectively, thusforming plural power groups A, B, C, D and E. Referring to FIG. 6, thesame suffix alphabetical characters common in the reference charactersdesignate identical power groups.

At the time of turning on the power supply or on other occasions, whenpower is supplied all at once to the plural processing circuits 221A,221B, 221C, 221D and 221E, so that these processing circuits 221A, 221B,221C, 221D and 221E are simultaneously turned on, the voltages appliedto each of the processing circuits 221A, 221B, 221C, 221D and 221E mayrapidly lower, so that the voltage needed to turn on the circuits is notsupplied, or a large current may flow into the processing circuits 221A,221B, 221C, 221D and 221E to cause them to fail. In the signalprocessing package 200_3 according to the present embodiment, the powercontrol section 224_3 regulates the timings of turning on the processingcircuits 221A, 221B, 221C, 221D and 221E.

Firstly, when the power supply to the communication unit 100 illustratedin FIG. 2 is turned on, the power is distributed to each of theelectrical circuit packages 200. In the signal processing package 200_3illustrated in FIG. 6, firstly the power control section 224_3 gives apower supply command to the power supply source 223A belonging to thepower group A, and the power supply source 223A supplies power to theprocessing circuit 221A of the power group A. As a result, theprocessing circuit 221A is turned on.

Similarly, the processing circuit 221B belonging to the power group B,the processing circuit 221C belonging to the power group C, theprocessing circuit 221D belonging to the power group D, and theprocessing circuit 221E belonging to the power group E are turned on oneafter the other.

In this way, since power is supplied, in such a manner that is shiftedin time, to the plural processing circuits 221A, 221B, 221C, 221D and221E, so that the processing circuits 221A, 221B, 221C, 221D and 221Eare each turned on at a different timing, the trouble caused by a sharpincrease in processing load can be reduced.

Further, when the plural power supply sources are, as illustrated inFIG. 6, arranged around one processing circuit, the distance between theprocessing circuit and power supply source is shortened, allowing moreefficient power supply. In addition, since the plural power supplysources are used, the power scale of each power supply source can bereduced, allowing downsizing of coils and capacitors for smoothing thepower supplied from the power supply source.

In communication apparatuses, the amount of processed data usuallyincreases or decreases intermittently. Thus, not only at the time ofturning on the communication apparatus but also when the amount ofcommunication data sharply increases, a large current may flow into theprocessing circuit to cause a large voltage drop, so that the processingcannot be executed.

In the communication unit 100 according to the present embodiment, theload of processing executed by each of the processing circuits 221A,221B, 221C, 221D and 221E is preliminarily predicted, and according tothis load, the power supplied to each of the processing circuits 221A,221B, 221C, 221D and 221E is regulated. The method of regulating powersupply will be described in detail below.

Of the five processing circuits 221A, 221B, 221C, 221D and 221Econstituting the signal processing package 200_3 illustrated in FIG. 6,the four processing circuits 221B, 221C, 221D and 221E serve to applyvarious types of signal processing to communication data sent from theformer-stage electrical interface package 200_2; and as the amount ofcommunication data increases, the load of processing executed by each ofthe processing circuits 221B, 221C, 221D and 221E also increases. Theremaining processing circuit 221A serves to apply a virus check to thecommunication data sent from the former-stage electrical interfacepackage 200_2; and the load of processing varies depending on whether ornot the communication data has an accompanying file attached thereto,rather than the amount of communication data.

Firstly, there will be described the method of regulating power supplyto the four processing circuits 221B, 221C, 221D and 221E in which theload of processing depends significantly on the amount of communicationdata.

Here, the processing circuit 221B provided with three power supplysources 223B will be described as representative of the four processingcircuits 221B, 221C, 221D and 221E.

FIG. 7 is a schematic configuration diagram of the processing circuit221B, the power supply source 223B for supplying power to the processingcircuit 221B, and the power control section 224_3.

It is noted that, while the processing circuit 221B is actually providedwith the three power supply sources 223B, only one power supply source223B is illustrated in FIG. 7 in order to simplify the explanation.

The power control section 224_3 includes, as illustrated in FIG. 7, anAD (analog-digital) converter 311, a digital filter 312, PWM controlcircuit 313, a power control circuit 314, and a pulse oscillator 315;and the power supply source 223B includes a switch element 321 and asmoothing filter 322.

In regulating power supply to the processing circuit 221B, as with theconventional analog power supply devices, there is basically used afeedback processing of regulating power to be supplied at a time afterthe present time based on power supplied at a time before the presenttime.

Firstly the AD converter 311 detects a voltage applied at a time beforethe present time by the power supply source 223B to the processingcircuit 221B, converts the detected voltage into a digital signal, andsends the digital signal to the digital filter 312. The digital filter312 calculates a difference between the detected voltage and a presetreference voltage, and averages the difference to produce an errorsignal. The produced error signal is sent to the PWM control circuit313.

The PWM control circuit 313 produces, based on a pulse signal generatedby the pulse oscillator 315 and the error signal sent from the digitalfilter 312, a control signal of a pulse width dependent on a controlvalue sent from the power control circuit 314, and sends the producedcontrol signal to the switch element 321. Processings performed in thePWM control circuit 313 and power control circuit 314 will be describedin detail later.

The switch element 321 performs ON/OFF control according to the controlsignal sent from the PWM control circuit 313, thus regulating the pulsewidth of input voltage. Further, a voltage having the regulated pulsewidth regulated passes through the smoothing filter 322, so that thevoltage applied to the processing circuit 221B is smoothed, and power issupplied to the processing circuit 221B. The power supplied to theprocessing circuit 221B will also be described in detail later.

For example, when the voltage applied to the processing circuit 221Blowers, the value of error signal produced by the digital filter 312increases, and thus the power control circuit 314 produces a controlsignal of a wider pulse width. As a result, “ON” time of the switchelement 321 lengthens, and thus the voltage applied to the processingcircuit 221B rises. As described above, the power supplied to theprocessing circuit 221B is regulated by the feedback control.

Further, according to the present embodiment, a current value flowinginto the processing circuit 221_2 of the former-stage electricalinterface package 200_2 is sent from the electrical interface package200_2 to the power control circuit 314 at every predetermined timing.Typically, as the amount of communication data to be processedincreases, the load of processing increases and thus a larger currentflows into the processing circuit. Since the value of current flowinginto the former-stage electrical interface package 200_2 is sent, theload of processing to be executed in the processing circuit 221B can bepredicted.

The power control circuit 314 sends a control signal every time thecurrent value is sent to the electric interface package 200_2. As thevalue of current acquired from the electrical interface package 200_2 islarger, the power control circuit 314 causes the AD converter 311 toreduce its detection voltage to a larger extent, and causes the digitalfilter 312 to use a smaller reference voltage, and causes the PWMcontrol circuit 313 to increase the pulse width of control signal. As aresult, the voltage applied from the power supply source 223B to theprocessing circuit 221B rises.

In this way, according to the present embodiment, the power to besupplied at a time after the present time is regulated based on thepower supplied at a time before the present time (feedback control) andat the same time, power supply is regulated according to the load ofprocessing executed by the former-stage electrical interface package200_2 (feedforward control) Consequently, power can be stably suppliedto the processing circuit, so that troubles caused by an increase inload in processing execution can be prevented.

In this case, while sufficient power is supplied to the processingcircuit 221B, when the voltage to be applied to the processing circuit221B does not reach the minimum voltage allowing execution ofprocessing, troubles such as flawed communication data may occur. In thecommunication unit 100 according to the present embodiment, the powersupplied to the processing circuit is regulated by raising or loweringof voltage; when the increase in load is predicted, the voltage ispreliminarily raised, so reliable processing execution is possible.

Here, when the power control circuit 314 goes out of control, the PWMcontrol circuit 313 is freed from the control by the power controlcircuit 314, and there is executed a processing for maintaining thevoltage applied to the processing circuit at a constant level.

FIG. 8 is a view illustrating the configuration of the power controlcircuit 314 and PWM control circuit 313, and a flow of data transmittedbetween the power control circuit 314 and PWM control circuit 313.

As illustrated in FIG. 8, in the signal processing package 200_3, thereare mounted a buffer 316 for storing a control signal (a voltage appliedto the processing circuit 221) sent at every predetermined timing fromthe power control circuit 314 to the PWM control circuit 313, and awatchdog 317 for monitoring operational abnormality of the power controlcircuit 314.

The buffer 316 is divided into plural storage areas 316 a; an initialvalue is preliminarily stored in the lowest storage area 316 a shown inthe lowest part of FIG. 8. In the buffer 316, data is stored in eachstorage area 316 a starting from the lowest one; when the uppermoststorage area 316 a is reached, data is overwritten starting from thedata stored in the storage area 316 a adjacent to the lowest one. Thebuffer 316 corresponds to an example of the storage section according tothe present invention.

Further, the PWM control circuit 313 is provided with a control memory313 a into which a control signal is written, and a monitoring memory313 b into which an initial value “1” is preliminarily written by ahardware.

In sending a control value (a voltage applied to the processing circuit221B) to the PWM control circuit 313, the power control circuit 314writes the control value into the control memory 313 a of the PWMcontrol circuit 313 and at the same time writes a value “0” indicatingan normal operation into the monitoring memory 313 b.

When receiving the control value from the power control circuit 314, thePWM control circuit 313 writes the control value written into thecontrol memory 313 a into the buffer 316.

The watchdog 317 monitors a value written into the monitoring memory 313b; when a value other than “0” indicating an normal operation is writteninto the monitoring memory 313 b, the watchdog 317 notifies operationalabnormality of the power control circuit 314 to the PWM control circuit313. When the power control circuit 314 malfunctions, an irregular valueis written into the monitoring memory 313 b. Since the value of themonitoring memory 313 b is monitored by the watchdog 317, abnormality ofthe power control circuit 314 can be unfailingly detected.

When informed of operational abnormality of the power control circuit314 by the watchdog 317, the PWM control circuit 313 gives a resetcommand to the power control circuit 314 and at the same time acquires acontrol value (a power supplied to the processing circuit 221B and avoltage applied to the processing circuit 221B) written in the buffer316 at a time before being informed of the operational abnormality andproduces a control signal of a pulse width dependent on the acquiredcontrol value. The produced control signal is sent to the switch element321 illustrated in FIG. 6, so the switch element 321 is turned on/offaccording to the control signal. As a result, a voltage of the samevalue as one written in the buffer 316 at a time before being informedof the operational abnormality, is applied to the processing circuit221.

When resetting of the power control circuit 314 is finished and “0”indicating a normal operation is written again into the monitoringmemory 313 b, the watchdog 317 notifies recovery of the power controlcircuit 314 to the PWM control circuit 313.

When informed of the recovery of the power control circuit 314, the PWMcontrol circuit 313 produces again a control signal according to acontrol value sent from the power control circuit 314.

In this way, in the communication unit 100 of the present embodiment,even when the power control circuit 314 itself goes out of control, itis possible to unfailingly prevent an excessive current from flowinginto the processing circuit 221, so the processing circuit 221 is notdamaged. Thus, the reliability of processing execution in the processingcircuit 221 can be improved.

Further, in the communication unit 100 of the present embodiment, poweris supplied in a phase shifted manner from plural power supply sources223 to each of the processing circuits 221, so that the apparentfrequency of power supplied to each of the processing circuits 221 israised.

FIG. 9 is a conceptual view illustrating power supplied from each of thethree power supply sources 223B to the processing circuit 221B.

In the power control circuit 314, when a voltage to be applied to theprocessing circuit 221B is determined, voltages applied by each of thethree power supply sources 223B_1, 223B_2 and 223B_3 to the processingcircuit 221B are separately regulated.

FIG. 9 illustrates: pulse signal P generated by the pulse oscillator315; power V1, V2 and V3 supplied from each of the power supply sources223B_1, 223B_2 and 223B_3 to the processing circuit 221B; and combinedpower V of power V1, V2 and V3.

The power control circuit 314 causes the power supply sources 223B_1,223B_2 and 223B_3 to supply power V1, V2 and V3, respectively, in aphase shifted manner. As a result, combined power V of a higherfrequency is supplied to the processing circuit 221B and thus a ripplecan be lowered.

In this way, plural power supply sources are connected to one processingcircuit, and power is supplied from the plural power supply sources in aphase shifted manner, so the switching frequency of power can be easilyraised.

The method of regulating power supply to the four processing circuits221B, 221C, 221D and 221E in which the load of processing depends on theamount of communication data, has been described above. There will nowbe described the method of regulating power supply to the processingcircuit 221A in which the load of processing varies according more towhether or not the communication data has an accompanying file attachedthereto, than to the amount of communication data.

In this processing circuit 221A, as with the other four processingcircuits 221B, 221C, 221D and 221E, the power to be supplied at a timeafter the present time is basically regulated based on the powersupplied at a time before the present time (feedback control) andfurther, a load of processing to be executed at a time after the presenttime is predicted based on a power control value at a time before thepresent time, so that power is regulated (feedforward control).

FIG. 10 is a schematic configuration diagram of the power supply source223A, power control section 224_3, and processing circuit 221A.

In the processing circuit 221A illustrated in FIG. 10, differently fromthe processing circuit 221B illustrated in FIG. 7, no current value issent from the former-stage electrical interface package 200_2 to thepower control section 224_3; instead, there is arranged a current valuedetection circuit 410 that detects a current value flowing into theprocessing circuit 221A.

In regulating the power supplied to the processing circuit 221A, firstlythe current value detection circuit 410 detects a current currentlyflowing into the processing circuit 221A and sends the detected currentvalue to the power control circuit 314.

The power control circuit 314 predicts a current value flowing into theprocessing circuit 221A at a time after the present time based on acurrent value flowing into the processing circuit 221A at a time beforethe present time, so that a voltage value to be applied to theprocessing circuit 221A is determined according to the predicted currentvalue. Practically, it is analyzed whether the change in current patternis gradual or rapid. When the change in current flowing in theprocessing circuit 221A is rapid, it is predicted that the amount ofdata currently processed by the processing circuit 221A is large andthus the load of processing execution is large. In this case, voltagedrop may continue to occur in the processing circuit 221A, so it isdetermined that a large voltage is to be applied to the processingcircuit 221A.

As an approach of predicting current flowing at a time after the presenttime based on current currently flowing, there can be used a regressionanalysis method or the like of predicting a subsequent numerical valueby a correlative relationship between plural numerical values. Theregression analysis method is a numerical value estimation method whichhas hitherto been widely used, and hence a detail explanation thereof isomitted in the present specification.

The power control circuit 314 controls based on the determined controlvoltage value, the AD converter 311, digital filter 312 and PWM controlcircuit 313. As a result, the determined control voltage value isapplied to the processing circuit 221, and power is supplied accordingto the load of processing.

When the load of processing at a time after the present time cannot bepredicted based on the load of the former-stage processing, if theestimation is made based on the load of processing by the own processingcircuit, the voltage applied to the processing circuit can be accuratelyregulated.

There has been described above an example in which a current valueflowing into the processing circuit during processing execution isdetected as the load of processing execution, but the load detectionsection according to the present invention may detect an amount ofprocessing data as the load of processing execution.

Also, there has been described above an example in which the powersupplied to the processing circuit is regulated by raising or loweringthe voltage applied to the processing circuit, but the power controlsection according to the present invention may control the powersupplied to the processing circuit by regulating the current valuesupplied to the processing circuit.

Also, there has been described above an example in which, whenoperational abnormality occurs in the power control section, the samepower as one at a time before the time when the operational abnormalityis detected is supplied to the processing circuit, but the supplysection according to the present invention may supply a predeterminedpower to the processing circuit when operational abnormality occurs inthe power control section.

1. A power supply device comprising: a supply section that suppliespower to a second processing device which sequentially processescommunication data transmitted from a first processing device inresponse to processing execution by the first processing device whichhas a processing circuit to process communication data; a load detectionsection that detects a load of processing execution by the firstprocessing device; and a power control section that causes the supplysection to increase or decrease power supply according to the magnitudeof load detected by the load detection section.
 2. The power supplydevice according to claim 1, wherein: in the supply section, voltage isvariable in supplying power; and the power control section causes thesupply section to increase or decrease power supply by raising orlowering the voltage of the supply section.
 3. The power supply deviceaccording to claim 1, wherein the first processing device and the secondprocessing device are incorporated in a communication apparatus andserve to apply a communication processing to data communicated by thecommunication apparatus.
 4. A communication apparatus comprising: afirst processing section that serves to apply a first communicationprocessing to communication data; a second processing section thatserves to apply a second communication processing to communication datatransmitted from the first processing section in response to processingexecution by the first processing section; a supply section thatsupplies power to the second processing section; a load detectionsection that detects a load of processing execution by the firstprocessing section; and a power control section that causes the supplysection to increase or decrease power supply according to the magnitudeof load detected by the load detection section.
 5. The communicationapparatus according to claim 4, wherein: in the supply section, voltageis variable in supplying power; and the power control section causes thesupply section to increase or decrease power supply by raising orlowering the voltage of the supply section.